Watchdog_States _Watchdog_Remove(
Watchdog_Control *the_watchdog
)
{
ISR_Level level;
Watchdog_States previous_state;
Watchdog_Control *next_watchdog;
_ISR_Disable( level );
previous_state = the_watchdog->state;
switch ( previous_state ) {
case WATCHDOG_INACTIVE:
break;
case WATCHDOG_BEING_INSERTED:
/*
* It is not actually on the chain so just change the state and
* the Insert operation we interrupted will be aborted.
*/
the_watchdog->state = WATCHDOG_INACTIVE;
break;
case WATCHDOG_ACTIVE:
case WATCHDOG_REMOVE_IT:
the_watchdog->state = WATCHDOG_INACTIVE;
next_watchdog = _Watchdog_Next( the_watchdog );
if ( _Watchdog_Next(next_watchdog) )
next_watchdog->delta_interval += the_watchdog->delta_interval;
if ( _Watchdog_Sync_count )
_Watchdog_Sync_level = _ISR_Nest_level;
_Chain_Extract_unprotected( &the_watchdog->Node );
break;
}
the_watchdog->stop_time = _Watchdog_Ticks_since_boot;
_ISR_Enable( level );
return( previous_state );
}
void _Watchdog_Insert(
Chain_Control *header,
Watchdog_Control *the_watchdog
)
{
ISR_Level level;
Watchdog_Control *after;
uint32_t insert_isr_nest_level;
Watchdog_Interval delta_interval;
insert_isr_nest_level = _ISR_Nest_level;
_ISR_Disable( level );
/*
* Check to see if the watchdog has just been inserted by a
* higher priority interrupt. If so, abandon this insert.
*/
if ( the_watchdog->state != WATCHDOG_INACTIVE ) {
_ISR_Enable( level );
return;
}
the_watchdog->state = WATCHDOG_BEING_INSERTED;
_Watchdog_Sync_count++;
restart:
delta_interval = the_watchdog->initial;
/*
* We CANT use _Watchdog_First() here, because a TICK interrupt
* could modify the chain during the _ISR_Flash() below. Hence,
* the header is pointing to volatile data. The _Watchdog_First()
* INLINE routine (but not the macro - note the subtle difference)
* casts away the 'volatile'...
*
* Also, this is only necessary because we call no other routine
* from this piece of code, hence the compiler thinks it's safe to
* cache *header!!
*
* Till Straumann, 7/2003 (gcc-3.2.2 -O4 on powerpc)
*
*/
for ( after = (Watchdog_Control *) ((volatile Chain_Control *)header)->first ;
;
after = _Watchdog_Next( after ) ) {
if ( delta_interval == 0 || !_Watchdog_Next( after ) )
break;
if ( delta_interval < after->delta_interval ) {
after->delta_interval -= delta_interval;
break;
}
delta_interval -= after->delta_interval;
/*
* If you experience problems comment out the _ISR_Flash line.
* 3.2.0 was the first release with this critical section redesigned.
* Under certain circumstances, the PREVIOUS critical section algorithm
* used around this flash point allowed interrupts to execute
* which violated the design assumptions. The critical section
* mechanism used here WAS redesigned to address this.
*/
_ISR_Flash( level );
if ( the_watchdog->state != WATCHDOG_BEING_INSERTED ) {
goto exit_insert;
}
if ( _Watchdog_Sync_level > insert_isr_nest_level ) {
_Watchdog_Sync_level = insert_isr_nest_level;
goto restart;
}
}
_Watchdog_Activate( the_watchdog );
the_watchdog->delta_interval = delta_interval;
_Chain_Insert_unprotected( after->Node.previous, &the_watchdog->Node );
the_watchdog->start_time = _Watchdog_Ticks_since_boot;
exit_insert:
_Watchdog_Sync_level = insert_isr_nest_level;
_Watchdog_Sync_count--;
_ISR_Enable( level );
}
void _Watchdog_Insert(
Watchdog_Header *header,
Watchdog_Control *the_watchdog
)
{
ISR_Level level;
Watchdog_Control *after;
uint32_t insert_isr_nest_level;
Watchdog_Interval delta_interval;
insert_isr_nest_level = _ISR_Nest_level;
_ISR_Disable( level );
/*
* Check to see if the watchdog has just been inserted by a
* higher priority interrupt. If so, abandon this insert.
*/
if ( the_watchdog->state != WATCHDOG_INACTIVE ) {
_ISR_Enable( level );
return;
}
the_watchdog->state = WATCHDOG_BEING_INSERTED;
_Watchdog_Sync_count++;
restart:
delta_interval = the_watchdog->initial;
for ( after = _Watchdog_First( header ) ;
;
after = _Watchdog_Next( after ) ) {
if ( delta_interval == 0 || !_Watchdog_Next( after ) )
break;
if ( delta_interval < after->delta_interval ) {
after->delta_interval -= delta_interval;
break;
}
delta_interval -= after->delta_interval;
_ISR_Flash( level );
if ( the_watchdog->state != WATCHDOG_BEING_INSERTED ) {
goto exit_insert;
}
if ( _Watchdog_Sync_level > insert_isr_nest_level ) {
_Watchdog_Sync_level = insert_isr_nest_level;
goto restart;
}
}
_Watchdog_Activate( the_watchdog );
the_watchdog->delta_interval = delta_interval;
_Chain_Insert_unprotected( after->Node.previous, &the_watchdog->Node );
the_watchdog->start_time = _Watchdog_Ticks_since_boot;
exit_insert:
_Watchdog_Sync_level = insert_isr_nest_level;
_Watchdog_Sync_count--;
_ISR_Enable( level );
}